In this project, a large storage tank was simulated in order to design the most efficient heating element configuration. A very viscous fluid was maintained at a high temperature with continuous flow in and out of the tank. The aim was to maximise the natural convection within the tank, find the optimum heating element configuration, reduce the energy consumption and to find the best location to place the temperature probes within the tank. The simulations were successfully conducted for a number of designs and the most efficient configuration based on optimum heat transfer and velocity distributions were selected. All the hot and cold spots within the tank were also identified to provide the best locations to place the temperature probes. In addition, the effects of external wind on the tank was also taken into consideration when deciding on the best heating element configuration, to minimise energy consumption.